Modular knee prothesis

ABSTRACT

Implant assemblies, systems, and methods for replacing a knee joint may include a method of revising a knee joint prosthesis implanted in a knee of a patient to provide increased stability to the knee joint prosthesis by replacing a first tibial insert with a second tibial insert that provides more constraint that the first tibial insert. A knee joint prosthesis system and kit are also provided that may include a tibial baseplate component, a femoral component, and a tibial insert that is selectively interchangeable with other tibial inserts to provide varying levels of constraint and stability to the knee joint prosthesis.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/537,106, entitled MODULAR KNEE PROSTHESIS, which was filed on Jul. 26, 2017. The above-referenced application is incorporated by reference herein as though set forth in its entirety.

TECHNICAL FIELD

The present disclosure relates to surgical devices, systems, instruments, and methods. More specifically, the present disclosure relates to orthopedic knee replacement surgical devices, instruments, systems, and methods.

BACKGROUND

A number of knee replacement options exist which may be implemented depending upon the level of compromise of the natural knee anatomy. The knee anatomy complex includes the knee joint between the femur distal end and the tibia proximal end, and the surrounding anterior and posterior cruciate ligaments (ACL, PCL), and medial and lateral collateral ligaments (MCL, LCL), which provide support and stabilization to the knee joint. When one or more ligaments are compromised, for example through injury, disease, or aging, a knee prosthesis system may be implanted to replace the knee joint.

In a situation where the anterior cruciate ligament is compromised, it may be removed and a cruciate retaining (CR) knee prosthesis system, which allows retention of the posterior cruciate ligament and the collateral ligaments, may be implanted. Typical CR knee prosthesis femoral components and tibial inserts have large U-shaped openings providing room for the extant PCL, MCL, and LCL ligaments.

In a case where both the anterior and posterior cruciate ligaments are compromised but, yet the collateral ligaments are functional, both the ACL and PCL may be removed, and a posterior stabilizing (PS) knee prosthesis system may be implanted. A typical PS tibial insert includes a central post, and many PS femoral components include a cam element extending between the medial and lateral condyles. The post and cam interact to provide stability in place of the removed PCL ligament.

In a case where the anterior and posterior cruciate ligaments are compromised, and the collateral ligaments are unstable, both the ACL and PCL may be removed and a constrained condylar knee (CCK) prosthesis system may be implanted. In a case where all four ligaments are compromised, all ligaments may be removed, and a hinge type knee replacement system may be implanted.

A typical knee prosthesis system includes a tibial bone anchoring component, a tibial articulating component, which may be called a tibial insert, and a femoral bone anchoring component. Since the tibial and femoral bone anchoring components are anchored to bone through various fasteners, cement, and/o bone ingrowth, it may be difficult and invasive to remove and replace either of the bone anchoring components, should the need arise. The tibial insert is typically made of polyethylene, and since it is not anchored to bone, is much more easily replaced if necessary. For example, a patient may have a CR knee prosthesis and then experience compromise of the PCL, thus requiring replacement of the CR knee prosthesis with a PS knee prosthesis. Or, a patient may have a PS knee prosthesis and then experience instability of the collateral ligaments, thus requiring replacement of the PS knee prosthesis with a CCK prosthesis.

SUMMARY

The various systems and methods of the present disclosure have been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available technology.

In some embodiments, a method for revising a knee joint prosthesis implanted in a knee of a patient, to provide increased stability to the knee joint prosthesis, may include accessing a knee joint prosthesis implanted in a knee of a patient. The knee joint prosthesis may include a tibial baseplate component implanted on a tibia of the patient, a femoral component implanted on a femur of the patient, and a first tibial insert implanted between the tibial baseplate component and the femoral component to form a first knee joint prosthesis assembly. The method may also include removing the first tibial insert from between the tibial baseplate component and the femoral component of the knee joint prosthesis and inserting a second tibial insert between the tibial baseplate component and the femoral component to form a second knee joint prosthesis assembly that is more constrained than the first knee joint prosthesis assembly, in order to provide increased stability to the knee joint prosthesis.

The femoral component may be a cruciate retaining femoral component. The first tibial insert may be a cruciate retaining tibial insert. The second tibial insert may be a posterior stabilizing tibial insert.

The femoral component may be a cruciate retaining femoral component. The first tibial insert may be a cruciate retaining tibial insert. The second tibial insert may be a constrained condylar knee tibial insert.

The femoral component may be a cruciate retaining femoral component. The first tibial insert may be a posterior stabilizing tibial insert. The second tibial insert may be a constrained condylar knee tibial insert.

The femoral component may be a posterior stabilizing femoral component. The first tibial insert may be a cruciate retaining tibial insert. The second tibial insert may be a posterior stabilizing tibial insert.

The femoral component may be a posterior stabilizing femoral component. The first tibial insert may be a cruciate retaining tibial insert. The second tibial insert may be a constrained condylar knee tibial insert.

The femoral component may be a posterior stabilizing femoral component. The first tibial insert may be a posterior stabilizing tibial insert. The second tibial insert may be a constrained condylar knee tibial insert.

In other embodiments, a knee joint prosthesis system for implantation in a knee of a patient may include a tibial baseplate component configured to be implanted on a tibia of a patient, a femoral component configured to be implanted on a femur of the patient, and a tibial insert configured to be implanted between the tibial baseplate component and the femoral component. The femoral component may include a cruciate retaining femoral component and/or a posterior stabilizing femoral component. The tibial insert may include a cruciate retaining tibial insert, a posterior stabilizing tibial insert, and/or a constrained condylar knee tibial insert. The cruciate retaining tibial insert, the posterior stabilizing tibial insert, and the constrained condylar knee tibial insert may be selectively interchangeable such that each of the cruciate retaining tibial insert, the posterior stabilizing tibial insert, and the constrained condylar knee tibial insert may be individually inserted between the tibial baseplate component and the femoral component to form a functioning knee joint replacement.

The tibial insert may be a posterior stabilizing tibial insert with a medial articulation portion, a lateral articulation portion, a central portion positioned between the medial articulation portion and the lateral articulation portion, and a post protruding superiorly from the central portion along a midline vertical axis. A superior end of the post may be shaped as a portion of a circle, as seen from a superior perspective, and the superior end of the post may define a circular envelope in a cross-section transverse to the midline vertical axis.

The superior end of the post may be shaped as a portion of a circle, as seen from a superior perspective, with a crescent shape with a concave recess toward a posterior end of the post.

The superior end of the post may be shaped as a portion of a circle, as seen from a superior perspective, with a convex protrusion toward a posterior end of the post.

The post may protrude superiorly from the central portion, from a base of the post to the superior end of the post. The post may further have a medial side and a lateral side. The medial side and the lateral side may each extend from the base of the post to the superior end of the post. The medial side and the lateral side may each taper inwardly from the superior end of the post toward the base of the post. The post may be widest at the superior end of the post and narrowest at the base of the post.

The medial side and the lateral side may each extend at an angle relative to the midline vertical axis, wherein the angle is within the range of 6° to 11°.

The angle may be approximately 6.5°.

In yet other embodiments, a modular knee joint replacement kit may include a tibial baseplate component configured to be implanted on a tibia of a patient, a femoral component configured to be implanted on a femur of the patient, and a tibial insert configured to be implanted between the tibial baseplate component and the femoral component. The femoral component may include a cruciate retaining femoral component and/or a posterior stabilizing femoral component. The tibial insert may include a cruciate retaining tibial insert, a posterior stabilizing tibial insert, and/or a constrained condylar knee tibial insert. The cruciate retaining tibial insert, the posterior stabilizing tibial insert, and the constrained condylar knee tibial insert may be selectively interchangeable such that each of the cruciate retaining tibial insert, the posterior stabilizing tibial insert, and the constrained condylar knee tibial insert may be individually inserted between the tibial baseplate component and the femoral component to form a functioning knee joint replacement. The modular knee joint replacement kit may also include a package that contains at least one tibial insert.

The package may further contains at least the tibial base plate and the at least one femoral component.

The at least one tibial insert may include a posterior stabilizing tibial insert with a medial articulation portion, a lateral articulation portion, a central portion positioned between the medial articulation portion and the lateral articulation portion, and a post protruding superiorly from the central portion along a midline vertical axis. A superior end of the post may be shaped as a portion of a circle, as seen from a superior perspective, and the superior end of the post may define a circular envelope in a cross-section transverse to the midline vertical axis.

The superior end of the post may be shaped as a portion of a circle, as seen from a superior perspective, and may have a crescent shape with a concave recess toward a posterior end of the post.

The superior end of the post may be shaped as a portion of a circle, as seen from a superior perspective, with a convex protrusion toward a posterior end of the post.

The post may protrude superiorly from the central portion, from a base of the post to the superior end of the post. The post may further have a medial side and a lateral side. The medial side and the lateral side may each extend from the base of the post to the superior end of the post. The medial side and the lateral side may each taper inwardly from the superior end of the post toward the base of the post. The post may be widest at the superior end of the post and narrowest at the base of the post. The medial side and the lateral side may each extend at an angle relative to the midline vertical axis. The angle may be within the range of 6° to 11°.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages, nature, and additional features of exemplary embodiments of the disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only exemplary embodiments and are, therefore, not to be considered limiting of the disclosure's scope, the exemplary embodiments of the disclosure will be described with additional specificity and detail through use of the accompanying drawings in which:

FIG. 1A is a perspective rear view of an assembly of the disclosure, including a posterior stabilizing femoral component and a tibial insert coupled in extension; FIG. 1B is a perspective front view of the assembly of FIG. 1A in flexion;

FIG. 2 is an exploded view of the assembly of FIG. 1A;

FIG. 3A is a posterior view of the tibial insert of FIG. 1A; FIG. 3B is an anterior view of the tibial insert of FIG. 1A; FIG. 3C is a superior view of the tibial insert of FIG. 1A; FIG. 3D is a medial side view of the tibial insert of FIG. 1A;

FIG. 4 is a top down view of the assembly of FIG. 1A;

FIG. 5 is a top down cross-sectional view of the assembly of FIG. 1A, taken along line B-B in FIG. 6;

FIG. 6 is a posterior cross-sectional view of the assembly of FIG. 1A, taken along line A-A in FIG. 5;

FIG. 7 is a top down cross-sectional view of the assembly of FIG. 1B, taken along line C-C in FIG. 8;

FIG. 8 is a posterior cross-sectional view of the assembly of FIG. 1B, taken along line D-D in FIG. 7;

FIG. 9 is a perspective rear view of an assembly of the disclosure, including a cruciate retaining femoral component and the tibial insert of FIG. 1A coupled in extension;

FIG. 10 is an exploded perspective rear view of the assembly of FIG. 9;

FIG. 11A is a perspective rear view of another tibial insert of the disclosure; FIG. 11B is a top view of the tibial insert of FIG. 11A; FIG. 11C is a posterior view of the tibial insert of FIG. 11A; FIG. 11D is an anterior view of the tibial insert of FIG. 11A; FIG. 11E is a bottom view of the tibial insert of FIG. 11A;

FIG. 12A is a perspective rear view of another tibial insert of the disclosure; FIG. 12B is a top view of the tibial insert of FIG. 12A; FIG. 12C is a bottom view of the tibial insert of FIG. co 12A; FIG. 12D is a posterior view of the tibial insert of FIG. 12A; FIG. 12E is an anterior view of the tibial insert of FIG. 12A; FIG. 12F is a medial side view of the tibial insert of FIG. 12A;

FIG. 13 is a chart demonstrating the interchangeability of the tibial inserts disclosed herein with various femoral components;

FIG. 14 is an exploded rear view of another assembly of the disclosure, including a posterior stabilizing femoral component and a posterior stabilizing tibial insert;

FIG. 15 is another exploded rear view of the assembly of FIG. 14;

FIG. 16A is a posterior view of the tibial insert of FIG. 14; FIG. 16B is an anterior view of the tibial insert of FIG. 14; FIG. 16C is a superior view of the tibial insert of FIG. 14; FIG. 16D is a medial side view of the tibial insert of FIG. 14;

FIG. 17 is an exploded rear view of another assembly of the disclosure, including a cruciate retaining femoral component with a keel and the posterior stabilizing tibial insert of FIG. 14;

FIG. 18 is another exploded rear view of the assembly of FIG. 17;

FIG. 19 is an exploded rear view of another assembly of the disclosure, including a cruciate retaining femoral component without a keel and the posterior stabilizing tibial insert of FIG. 14;

FIG. 20 is another exploded rear view of the assembly of FIG. 19;

FIG. 21A is a perspective rear view of another tibial insert of the disclosure; FIG. 21B is a top view of the tibial insert of FIG. 21A; FIG. 21C is a posterior view of the tibial insert of FIG. 21A; FIG. 21D is an anterior view of the tibial insert of FIG. 21A; FIG. 21E is a bottom view of the tibial insert of FIG. 21A;

FIG. 22A is a perspective rear view of another tibial insert of the disclosure; FIG. 22B is a top view of the tibial insert of FIG. 22A; FIG. 22C is a bottom view of the tibial insert of FIG. 22A; FIG. 22D is a posterior view of the tibial insert of FIG. 22A; FIG. 22E is an anterior view of the tibial insert of FIG. 22A; FIG. 22F is a medial side view of the tibial insert of FIG. 22A;

FIG. 23A is a perspective front view of the femoral component of FIG. 14 coupled to one or more augments of the present disclosure; FIG. 23B is a medial side view of the femoral co component of FIG. 23A;

FIG. 24A is a perspective top view of a femoral trial component of the disclosure; FIG. 24B is a perspective rear view of the femoral trial component of FIG. 24A; FIG. 24C is a lateral side view of the femoral trial component of FIG. 24A; FIG. 24D is a medial side view of the femoral trial component of FIG. 24A; FIG. 24E is an anterior view of the femoral trial component of FIG. 24A; FIG. 24F is a posterior view of the femoral trial component of FIG. 24A; FIG. 24G is a superior view of the femoral trial component of FIG. 24A; FIG. 24H is an inferior view of the femoral trial component of FIG. 24A;

FIG. 25A is a perspective rear view of a posterior stabilizing notch cutting guide assembly of the disclosure; FIG. 25B is another perspective rear view of the posterior stabilizing notch cutting guide assembly of FIG. 25A; FIG. 25C is a medial side view of the posterior stabilizing notch cutting guide assembly of FIG. 25A; FIG. 25D is a top view of the posterior stabilizing notch cutting guide assembly of FIG. 25A;

FIG. 26 is a partial exploded view of the posterior stabilizing notch cutting guide assembly of FIG. 25A;

FIG. 27A is a posterior view of the posterior stabilizing notch cutting guide assembly of FIG. 25A above the femoral trial component of FIG. 24A; FIG. 27B is posterior view of the posterior stabilizing notch cutting guide assembly of FIG. 27A coupled to the femoral trial component of FIG. 27A;

FIG. 28A is a perspective rear view of a posterior stabilizing trial attachment of the disclosure; FIG. 28B is another perspective rear view of the posterior stabilizing trial attachment of FIG. 28A; FIG. 28C is a perspective front view of the posterior stabilizing trial attachment of FIG. 28A; FIG. 28D is a perspective side view of the posterior stabilizing trial attachment of FIG. 28A;

FIG. 29A is a posterior view of the posterior stabilizing trial attachment of FIG. 28A above the femoral trial component of FIG. 24A; FIG. 29B is a posterior view of the posterior stabilizing trial attachment of FIG. 29A coupled to the femoral trial component of FIG. 29A;

FIG. 30A is a perspective rear view of a drill and broach guide assembly of the disclosure; FIG. 30B is a perspective bottom view of the drill and broach guide assembly of FIG. 30A; FIG. 30C is a top view of the drill and broach guide assembly of FIG. 30A; FIG. 30D is a bottom view of the drill and broach guide assembly of FIG. 30A;

FIG. 31 is a partial exploded view of the drill and broach guide assembly of FIG. 30A;

FIG. 32A is a posterior view of the drill and broach guide assembly of FIG. 30A above the femoral trial component of FIG. 24A; FIG. 32B is a posterior view of the drill and broach guide assembly of FIG. 32A coupled to the femoral trial component of FIG. 32A;

FIG. 33A is a perspective front view of a cruciate retaining trial attachment of the disclosure; FIG. 33B is a perspective rear view of the cruciate retaining trial attachment of FIG. 33A; FIG. 33C is a perspective bottom view of the cruciate retaining trial attachment of FIG. 33A; FIG. 33D is a top view of the cruciate retaining trial attachment of FIG. 33A;

FIG. 34A is a posterior view of the cruciate retaining trial attachment of FIG. 33A above the femoral trial component of FIG. 24A; FIG. 34B is a posterior view of the cruciate retaining trial attachment of FIG. 34A coupled to the femoral trial component of FIG. 34A;

FIG. 35A is a perspective rear view of another femoral trial component of the disclosure; FIG. 35B is a posterior view of the femoral trial component of FIG. 35A; FIG. 35C is an anterior view of the femoral trial component of FIG. 35A;

FIG. 36 is a flow chart diagram of a method for preparing and trialing a femoral bone with a femoral trial component;

FIG. 37 is a flow chart diagram of a method for revising a knee joint prosthesis to provide increased stability;

FIG. 38A is a perspective front view of a tibial tray of the disclosure; FIG. 38B is a perspective rear view of the tibial tray of FIG. 38A; FIG. 38C is an anterior view of the tibial tray of FIG. 38A; FIG. 38D is a posterior view of the tibial tray of FIG. 38A; FIG. 38E is a bottom view of the tibial tray of FIG. 38A; FIG. 38F is a top view of the tibial tray of FIG. 38A; and

FIG. 39 is an exploded view of a tibial tray mounting system of the disclosure that utilizes the tibial tray of FIG. 38A.

It is to be understood that the drawings are for purposes of illustrating the concepts of the disclosure and may not be to scale. Furthermore, the drawings illustrate exemplary embodiments and do not represent limitations to the scope of the disclosure.

DETAILED DESCRIPTION

Exemplary embodiments of the disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the disclosure, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus, instruments, systems, and methods, as represented in the Figures, is not intended to limit the scope of the disclosure, as claimed, but is merely representative of exemplary embodiments of the disclosure.

Disclosed herein are components for a modular knee prosthesis system. This system may allow for revision procedures by replacement of only the tibial insert, allowing the originally implanted femoral and tibial anchoring components to remain implanted. The system may include CR tibial inserts, PS tibial inserts, and/or CCK tibial inserts. Any one of these tibial inserts may be interchangeably used with CR and/or PS femoral components disclosed herein to provide the stabilization needed to substitute for compromised or removed ligaments. The system may be used with any suitable tibial baseplate component, or tibial tray, to support the tibial insert. The PS tibial inserts disclosed herein may include tapered posts that permit the inserts to be used with cruciate retaining (CR) femoral components and/or posterior stabilizing (PS) femoral components.

Referring to FIGS. 1A-2, an assembly 10 for an implantable knee prosthesis is shown including a femoral component 14 and a tibial insert 12. The femoral component 14 and tibial insert 12 are shown coupled in extension in FIG. 1A, coupled in flexion in FIG. 1B, and shown in an exploded view in FIG. 2. The tibial insert 12 may be further coupled to a tibial baseplate component (not shown) which may be implanted in a prepared tibia of a patient (also not shown). The femoral component 14 and tibial insert 12 illustrated in FIGS. 1A-2 are right femoral and tibial insert components. Left femoral and tibial insert components (not shown) would be mirror images of the right femoral and tibial insert components shown in FIGS. 1A-2. The femoral component 14 may also be referred to as a posterior stabilizing femoral component 14 (or “PS femoral component”) and the tibial insert 12 may also be referred to as a posterior stabilizing tibial insert (or “PS insert”).

FIGS. 3A-3D show the PS insert 12 of FIGS. 1A-2 in isolation. The PS insert 12 may include a fixation side 20, which may be an inferior side, opposite an articulation side 22, which may be a superior side. The articulation side 22 may include a medial articulation portion 24 having a medial condylar articulation surface 25 and a lateral articulation portion 26 having a lateral condylar articulation surface 27. A central portion 28 may separate the medial articulation portion 24 from the lateral articulation portion 26. A post 30 may protrude superiorly from the central portion 28 and extend from a post base 38 to a post top or post superior end 40. From the anterior perspective (shown in FIG. 3B) and/or the posterior perspective (shown in FIG. 3A), the post 30 may have its maximum medial-lateral or horizontal width toward the post superior end 40 of the post 30, and its minimum medial-lateral or horizontal width toward the post base 38 of the post 30. The post 30 may also be bilaterally symmetrical from the anterior and/or posterior perspectives. A recess 45 may be formed posterior to the central portion 28, between the medial and lateral articulation portions 24, 26, and may provide room for a posterior cruciate ligament (not shown). The PS insert 12 may further include an insert base 46, which may further include an engagement feature 48 for engagement with a tibial baseplate component.

Continuing with FIGS. 1A-3D, the post 30 may have an articulation surface 31 extending around the post 30 on the medial, posterior, lateral, and anterior aspects of the post 30. The articulation surface 31 may include a medial articulation surface 32, a lateral articulation surface 34, an anterior post surface 36, and a posterior articulation surface 42. The medial and lateral articulation surfaces 32, 34 may be non-parallel to one another and taper inward from the post superior end 40 to the post base 38 relative to an insert midline vertical axis 2, as shown in FIGS. 3A and 3B. As shown in FIG. 3A, an angle θ between the vertical axis 2 and each tapered surface 32, 34 may be about 6.5°, in at least one embodiment. Since the post 30 may be bilaterally symmetrical, the angle θ may be the same on both the medial and lateral articulation surfaces 32, 34 of the post 30. In other embodiments of the disclosure, angle θ may range from about 6° to 11° degrees. The medial articulation surface 32 may be continuous with the medial condylar articulation surface 25, and the lateral articulation surface 34 may be continuous with the lateral condylar articulation surface 27, as can been further seen in cross-section in FIGS. 6 and 8. The anterior post surface 36 may extend between the medial and lateral articulation surfaces 32, 34 and may be convexly rounded. The anterior post surface 36 may also taper outward from the post superior end 40 to the post base 38 relative to the midline vertical axis 2, as best seen in FIG. 3D. In other embodiments of the PS insert 12, the anterior post surface 36 may include less or no taper.

Referring to FIG. 3C, the boundary of the post superior end 40 defines a rounded rim 44 shaped as a portion of a circle defined by a circular envelope 47, as seen from a superior perspective. The post superior end 40 and rim 44 may be crescent-shaped with a concave recess toward a posterior end of the post 30 as shown, and may permit passage of the posterior cruciate ligament. The post superior end 40 may be circular; the rim 44 may provide increased rotational range of motion and surface contact against the femoral component 14 in comparison to traditional posts with a more square or rectangular shape and no rim. Thus, the rounded post superior end 40 and rim 44 may allow for surface contact with the femoral component 14 in contrast to the mere point or edge contact that is achieved by traditional posts that do not have these features.

The PS femoral component 14 depicted in FIGS. 1-8 may include a cam element or cam bar 50 and a box structure 52 for providing posterior stabilization in place of absent ligaments. The cam bar 50 may include a cam articulating surface 51 which may contact the posterior articulation surface 42 of the post 30 during flexion, as in FIGS. 1B and 7. An internal articulation surface 54 may reside on the inside of the box structure 52 and may contact the post 30 during articulation and rotation of the knee joint. The internal articulating surface 54 may be concavely curved, and may contact the rim 44 of the post 30 during axial rotation of the knee joint about the post. The PS femoral component 14 may further include a medial condyle 60 having a medial condylar articulation surface 62, and a lateral condyle 64 having a lateral condylar articulation surface 66. The medial and lateral condylar articulation surfaces 62, 66 may articulate against the PS insert 12 medial and lateral condylar articulation surfaces 25, 27 respectively. A gap 68 may be formed between the medial and lateral condyles 60, 64, with the cam bar 50 extending medial-laterally across the gap 68. The internal articulation surface 54 may include a medial portion 70 continuous with a lateral portion 72. In the embodiment depicted, a fixation post 74 may protrude superiorly from the PS femoral component 14. However, in other embodiments of the PS femoral component 14, the fixation post 74 may be absent and/or other fixation features such as posts, spikes, pegs, webs, keels or teeth may be present to affix the PS femoral component 14 to a prepared femur (not shown).

Referring to FIGS. 9 and 10, another assembly 110 embodiment of the disclosure may include the PS insert 12 of FIGS. 1-8 coupled with a cruciate retaining femoral component 114 (or “CR femoral component”). The CR femoral component 114 may include medial and lateral condyles 160, 164, with a gap 168 formed between the medial and lateral condyles 160, 164. As a CR femoral component 114, no cam bar or box may be present. The medial and lateral condyles 160, 164 may include medial and lateral condylar articulation surfaces 162, 166, and an internal articulation surface 154 with medial and lateral articulating surfaces 170, 172.

The medial and lateral articulation surfaces 32, 34 of the post 30 may be tapered and may permit natural articulation of the CR femoral component 114 with the PS insert 12, which may not be achievable if the post 30 were not tapered. For example, if the post 30 had straight sides instead of tapered sides, the wider width of the post 30 at the base of the post 30 would interfere with the internal articulating surfaces 170, 172 of the medial and lateral condyles 160, 164. When the PS femoral component 14 is coupled with the PS insert 12 to form assembly 10, as in FIG. 1A and FIG. 4, the circular shape of the post superior end 40 in combination with the tapered medial and lateral articulation surfaces 32, 34 of the post 30, may permit the PS femoral component 14 to articulate relative to the PS insert 12 in the manner of a posterior stabilized femoral component. However, when the PS insert 12 is paired and implanted with the CR femoral component 114, the resultant assembly 110 may provide the native articulation and rotation of co a cruciate retaining implant.

Referring to FIGS. 11A-11E, an alternative embodiment of a tibial insert 212 is shown. Tibial insert 212 may be referred to as a cruciate retaining tibial insert 212 (or “CR insert”). In a system of the disclosure, CR insert 212 may be implanted with the CR femoral component 114 and a tibial baseplate component (not shown) to form a cruciate retaining knee prosthesis system. The CR insert 212 may include a fixation side 220, which may be an inferior side, opposite an articulation side 222, which may be a superior side. The articulation side 222 may include a medial articulation portion 224 having a medial condylar articulation surface 225 and a lateral articulation portion 226 having a lateral condylar articulation surface 227. A central portion 228 may separate the medial articulation portion 224 from the lateral articulation portion 226. A recess 245 may be formed posterior to the central portion 228, between the medial and lateral articulation portions 224, 226, and may provide room for a posterior cruciate ligament. The CR insert 212 may further include an insert base 246 and an engagement feature 248 for engagement with a tibial baseplate component. The CR insert 212 may be coupled with the CR femoral component 114 to form a cruciate retaining assembly. This assembly may be implanted with a suitable tibial baseplate as a cruciate retaining knee prosthesis. The CR insert 212 may also be coupled with the PS femoral component 14 and implanted with a suitable tibial baseplate.

Referring to FIGS. 12A-12F, another alternative embodiment of a tibial insert 312 is shown. The tibial insert 312 may be referred to as a constrained condylar knee (CCK) tibial insert 312 (or “CCK insert”). The CCK insert 312 may include a fixation side 320, which may be an inferior side, opposite an articulation side 322, which may be a superior side. The articulation side 322 may include a medial articulation portion 324 having a medial condylar articulation surface 325 and a lateral articulation portion 326 having a lateral condylar articulation surface 327. A central portion 328 may separate the medial articulation portion 324 from the lateral articulation portion 326. A post 330 may protrude superiorly from the central portion 328, and extend from a post base 338 to a top, or post superior end 340. From the anterior perspective, as shown in FIG. 12E, and the posterior perspective, as shown in FIG. 12D, the post 330 may have its maximum medial-lateral or horizontal width at the superior end 340 of the post 330, and its minimum medial-lateral or horizontal width at the post base 338 of the post 330. The post 330 may be bilaterally co symmetrical from the anterior and posterior perspectives. The CCK insert 312 may further include an insert base 346 and an engagement feature 348 for engagement with a tibial tray (not shown).

The post 330 may have an articulation surface 331 extending around the post 330 on the medial, posterior, lateral, and anterior aspects of the post 330. The articulation surface 331 may include a medial articulation surface 332, a lateral articulation surface 334, an anterior post surface 336, and a posterior articulation surface 342. The medial and lateral articulation surfaces 332, 334 may taper slightly inward from the post superior end 340 to the post base 338 of the post 330 relative to an insert midline vertical axis 2. However, some embodiments of CCK insert 312 may include no taper of the medial and lateral articulation surfaces 332, 334. The medial articulation surface 332 may be continuous with the medial condylar articulation surface 325, and the lateral articulation surface 334 may be continuous with the lateral condylar articulation surface 327. The anterior post surface 336 may extend between the medial and lateral surfaces 332, 334 and may be convexly rounded. The anterior post surface 336 may taper outward from the post superior end 340 to the post base 338 relative to the midline axis 2, as best seen in FIG. 12F. In other embodiments of the CCK insert 312, the anterior post surface 336 may include less taper, more taper, and/or no taper. The post 330 of the CCK insert 312 may be wider and bigger in diameter than the post 30 of PS insert 12, for example to provide increased stability in the case of removal of the collateral ligaments.

Referring to FIG. 12B, the boundary of the post superior end 340 may define a rounded rim 344 shaped as a portion of a circle, from a superior perspective. The post superior end 340 and rim 344 may be semi-circular as shown, however the rim 344 may define a circular envelope 347. The post superior end 340 may be circular and rim 344 may provide increased surface contact and rotational range of motion when coupled and implanted with the PS femoral component 14 in comparison to traditionally shaped posts with a more square or rectangular shaped post. Thus, the rounded post superior end 340 and rim 344 may allow for surface contact with the femoral component 14 in contrast to the mere point or edge contact that is achieved by traditional posts that do not have these features. The CCK insert 312 may be coupled with the PS femoral component 14 to form a constrained condylar knee assembly, and this assembly may be implanted with a suitable tibial baseplate as a constrained condylar knee prosthesis. The CCK insert 312 may also be coupled with the CR femoral component 114 and implanted with a suitable tibial baseplate. Thus, all of the tibial inserts 12, 212, and 312 disclosed herein are interchangeable with both the CR femoral component 114 and the PS femoral component 14. FIG. 13 is a chart showing the potential combinations of components.

The tibial inserts 12, 212, 312, PS femoral component 14 and CR femoral component 114 may be grouped together as a modular knee replacement system and provided as a kit in one or more packages, in one non-limiting example. Another kit may include a CR femoral component 114, a PS insert 12 and a CR insert 212, in one or more packages in another non-limiting example. Yet another kit may include a PS femoral component 14, a PS insert 12, a CR insert 212, and a CCK insert 312, in one or more packages in yet another non-limiting example. However, it will also be understood that other kit embodiments may utilize any of the tibial inserts and/or femoral components described herein in any number or combination, in one or more packages. Furthermore, other components may also be including in any kit described herein, such as suitable tibial baseplate components, patellar components, etc., in one or more packages. It will also be understood that any of the tibial inserts disclosed herein may be formed of vitamin E polyethylene, highly cross linked polyethylene, ultra-high molecular weight polyethylene (UHMWPE), or any other suitable material.

In a method of the disclosure, a patient may initially experience compromise of the anterior cruciate ligament. The ACL may be removed, and a CR type prosthesis may be implanted, including a CR femoral component 114, a CR insert 212, and a tibial baseplate component. Later, the same patient may experience compromise of the PCL and may need additional stabilization of the knee joint. The PCL may be removed, the CR tibial insert 212 may be removed, and a PS tibial insert 12 of the disclosure may be inserted between the originally implanted CR femoral component 114 and the tibial baseplate component, thus providing additional stability for the missing PCL. Even later, the same patient may experience instability of the collateral ligaments. The PS tibial insert 12 may be removed, and the CCK tibial insert 312 of the disclosure may be inserted between the originally implanted CR femoral component 114 and the tibial baseplate component. Thus, the patient may progress from a CR knee prosthesis, to a PS knee prosthesis, and finally to a CCK knee prosthesis without requiring replacement of the originally implanted femoral and/or tibial baseplate components. The interchangeability of the inserts 12, 212, 312 permit replacement of only the tibial insert component in order to provide increasing levels of support and stability to the knee joint.

In another method of the disclosure, a patient may initially experience compromise of both the ACL and the PCL. These ligaments may be removed, and a PS type prosthesis may be implanted, including a PS femoral component 14, a PS insert 12, and a tibial baseplate component. Later, the same patient may experience instability of the collateral ligaments. The PS insert 12 may be removed, and a CCK insert 312 may be inserted between the originally implanted PS femoral component 14 and the tibial baseplate component. Thus, the patient may progress from a PS knee prosthesis to a CCK knee prosthesis without requiring replacement of the originally implanted PS femoral component 14 and tibial baseplate component.

Referring to FIGS. 14 and 15, another assembly 1010 of the disclosure for an implantable knee prosthesis is shown in various exploded rear views. The assembly 1010 may include a femoral component 1014 and a tibial insert 1012. The tibial insert 1012 may be further coupled to a tibial baseplate component (not shown) which may also be implanted in a prepared tibia of a patient (not shown). The femoral component 1014 and tibial insert 1012 illustrated in FIGS. 14 and 15 are right side femoral and tibial insert components. Left side femoral and tibial insert components (not shown) would be mirror images of the right side femoral and tibial insert components that are shown in FIGS. 14 and 15. The femoral component 1014 may also be referred to as a posterior stabilizing femoral component 1014 (or “PS femoral component”) and the tibial insert 1012 may also be referred to as a posterior stabilizing tibial insert (or “PS insert”).

FIGS. 16A-16D show the PS insert 1012 of FIGS. 15 and 14 in isolation. The PS insert 1012 may include a fixation side 1020, which may be an inferior side, opposite an articulation side 1022, which may be a superior side. The articulation side 1022 may include a medial articulation portion 1024 having a medial condylar articulation surface 1025 and a lateral articulation portion 1026 having a lateral condylar articulation surface 1027. A central portion 1028 may separate the medial articulation portion 1024 from the lateral articulation portion 1026. A post 1030 may protrude superiorly from the central portion 1028 and extend from a post base 1038 to a post top 1040 or post superior end. From the anterior perspective (shown in FIG. co 16B) and/or the posterior perspective (shown in FIG. 16A), the post 1030 may have its maximum medial-lateral or horizontal width toward the top 1040 of the post 1030, and its minimum medial-lateral or horizontal width toward the base 1038 of the post 1030. The post 1030 may also be bilaterally symmetrical from the anterior and/or posterior perspectives. A recess 1045 may be formed posterior to the central portion 1028, between the medial and lateral articulation portions 1024, 1026, and may provide room for a posterior cruciate ligament (not shown). The PS insert 1012 may further include an insert base 1046, which may further include an engagement feature 1048 for engagement with a tibial baseplate component.

Continuing with FIGS. 14-16D, the post 1030 may have an articulation surface 1031 extending around the post 1030 on the medial, posterior, lateral, and anterior aspects of the post 1030. The articulation surface 1031 may include a medial articulation surface 1032, a lateral articulation surface 1034, an anterior post surface 1036, and a posterior articulation surface 1042. The medial and lateral articulation surfaces 1032, 1034 may be non-parallel to one another and taper inward from the post superior end 1040 to the post base 1038 relative to an insert midline vertical axis 1002, as shown in FIGS. 16A and 16B. As shown in FIG. 16A, an angle θ between the vertical axis 1002 and each tapered surface 1032, 1034 may be about 6.5°, in at least one embodiment. Since the post 1030 may be bilaterally symmetrical, the angle θ may be the same on both the medial and lateral sides 1032, 1034 of the post 1030. In other embodiments of the disclosure, angle θ may range from about 6° to 11° degrees. The medial articulation surface 1032 may be continuous with the medial condylar articulation surface 1025, and the lateral articulation surface 1034 may be continuous with the lateral condylar articulation surface 1027. The anterior post surface 1036 may extend between the medial and lateral surfaces 1032, 1034 and may be convexly rounded. The anterior post surface 1036 may also taper outward from the post superior end 1040 to the post base 38 relative to the insert midline vertical axis 1002, as best seen in FIG. 16D. In other embodiments of the PS insert 1012, the anterior post surface 1036 may include less taper, more taper, and/or no taper. A midline medial-lateral axis 1004 and a mid-line anterior-posterior axis 1006 are also shown.

Referring to FIG. 16C, the boundary of the superior end 1040 may define a rounded rim 1044 shaped as a portion of a circle defined by a circular envelope 1047, as seen from a co superior perspective. The superior end 1040 and rim 1044 may have a convex protrusion 1041 toward a posterior end of the post 1030 as shown, and may permit passage of the posterior cruciate ligament. The circular superior end 1040 with rim 1044 may provide increased rotational range of motion and surface contact against the femoral component 1014 in comparison to traditional posts with a more square or rectangular shape and no rim. Thus, the rounded superior end 1040 and rim 1044 may allow for greater surface contact with the femoral component 1014 in contrast to the mere point or edge contact that is achieved by traditional posts that do not have these features.

The PS femoral component 1014 depicted in FIGS. 14-15 may include augment fixation apertures 1080, impact driver apertures 1090, a cam element or cam bar 1050, and a box structure 1052 for providing posterior stabilization in place of absent ligaments. The cam bar 1050 may include a cam articulating surface 1051 which may contact the posterior articulation surface 1042 of the post 1030 during flexion. An internal articulation surface 1054 may reside on the inside of the box structure 1052 and may contact the post 1030 during articulation and rotation of the knee joint. The internal articulating surface 1054 may be concavely curved, and may contact the rim 1044 of the post 1030 during axial rotation of the knee joint about the post 1030. The PS femoral component 1014 may further include a medial condyle 1060 having a medial condylar articulation surface 1062, and a lateral condyle 1064 having a lateral condylar articulation surface 1066. The medial and lateral condylar articulation surfaces 1062, 1066 may articulate against the PS insert 1012 medial and lateral articulation surfaces 1025, 1027 respectively. A gap 1068 may be formed between the medial and lateral condyles 1060, 1064, with the cam bar 1050 extending medial-laterally across the gap 1068. The internal articulation surface 1054 may include a medial portion 1070 continuous with a lateral portion 1072. In the embodiment depicted, a fixation post 1074 may protrude superiorly from the PS femoral component 1014. However, in other embodiments of the PS femoral component 1014, the fixation post 1074 may be absent and/or other fixation features such as posts, spikes, pegs, webs, keels or teeth may be present to affix the PS femoral component 1014 to a prepared femur (not shown).

Referring to FIGS. 17 and 18, another assembly 1110 embodiment of the disclosure may include the PS insert 1012 of FIGS. 14-16D coupled with a cruciate retaining femoral component 1114 (or “CR femoral component”). The CR femoral component 1114 may include, a keel 1120, fixation members 1130, impact driver apertures 1190, and medial and lateral condyles 1160, 1164 with a gap 1168 formed between the condyles 1160, 1164. As a CR femoral component 1114, no cam bar or box may be present. The condyles 1160, 1164 may include medial and lateral condylar articulation surfaces 1162, 1166, and an internal articulation surface 1154 with medial and lateral portions 1170, 1172.

The tapered sides 1032, 1034 of the post 1030 may permit natural articulation of the CR femoral component 1114 with the PS insert 1012, which may not be achievable if the post 1030 were not tapered. For example, if the post 1030 had straight sides instead of tapered sides, the wider width of the post 1030 at the base of the post 1030 may interfere with the internal articulating surfaces 1170, 1172 of the condyles 1160, 1164. When the PS femoral component 1014 is coupled with the PS insert 1012 to form assembly 1010, as in FIGS. 14 and 15, the circular shape of the post superior end 1040 in combination with the tapered medial and lateral surfaces 1032, 1034 of the post 1030, may permit the PS femoral component 1014 to articulate relative to the PS insert 1012 in the manner of a posterior stabilized femoral component. However, when the PS insert 1012 is paired and implanted with the CR femoral component 1114, the resultant assembly 1110 may provide the native articulation and rotation of a cruciate retaining implant.

Referring to FIGS. 19 and 20, another assembly 2110 embodiment of the disclosure may include the PS insert 1012 of FIGS. 14-16D coupled with a cruciate retaining femoral component 2114 (or “CR femoral component”). The CR femoral component 2114 may not include a keel, as opposed to the CR femoral component 1114 shown in FIGS. 17 and 18, and the CR femoral component 2114 may be configured for cemented and/or cementless fixation to a femoral bone. The CR femoral component 2114 may include fixation members 2130, impact driver apertures 2190, and medial and lateral condyles 2160, 2164 with a gap 2168 formed between the condyles 2160, 2164. As a CR femoral component 2114, no cam bar or box may be present. The condyles 2160, 2164 may include medial and lateral condylar articulation surfaces 2162, 2166, and an internal articulation surface 2154 with medial and lateral portions 2170, 2172.

The tapered sides 1032, 1034 of the post 1030 may permit natural articulation of the CR femoral component 2114 with the PS insert 1012, which may not be achievable if the post 1030 were not tapered. For example, if the post 1030 had straight sides instead of tapered sides, the wider width of the post 1030 at the base 1038 of the post 1030 may interfere with the internal articulating surfaces 2170, 2172 of the condyles 2160, 2164. When the PS femoral component 1014 is coupled with the PS insert 1012 to form assembly 1010, as in FIGS. 14 and 15, the circular shape of the post superior end 1040 in combination with the tapered medial and lateral surfaces 1032, 1034 of the post 1030, may permit the PS femoral component 1014 to articulate relative to the PS insert 1012 in the manner of a posterior stabilized femoral component. However, when the PS insert 1012 is paired and implanted with the CR femoral component 2114, the resultant assembly 2110 may provide the native articulation and rotation of a cruciate retaining implant.

Referring to FIGS. 21A-21E, an alternative embodiment of a tibial insert 1212 is shown. The tibial insert 1212 may be referred to as a cruciate retaining tibial insert 1212 (or “CR insert”). In a system of the disclosure, the CR insert 1212 may be implanted with the CR femoral components 114, 1114, 2114 and a tibial baseplate component (not shown) to form a cruciate retaining knee prosthesis system. The CR insert 1212 may include a fixation side 1220, which may be an inferior side, opposite an articulation side 1222, which may be a superior side. The articulation side 1222 may include a medial articulation portion 1224 having a medial condylar articulation surface 1225 and a lateral articulation portion 1226 having a lateral condylar articulation surface 1227. A central portion 1228 may separate the medial articulation portion 1224 from the lateral articulation portion 1226. A recess 1245 may be formed posterior to the central portion 1228, between the medial and lateral articulation portions 1224, 1226, and may provide room for a posterior cruciate ligament. The CR insert 1212 may further include an insert base 1246 and an engagement feature 1248 for engagement with a tibial baseplate component.

The CR insert 1212 may be coupled with CR femoral components 114, 1114, 2114 to form a cruciate retaining assembly. This cruciate retaining assembly may be implanted with a suitable tibial baseplate as a complete cruciate retaining knee prosthesis. The CR insert 1212 may also be coupled with PS femoral components 14, 1014 to form a posterior stabilizing assembly and implanted with a suitable tibial baseplate as a complete posterior stabilizing knee prosthesis.

Referring to FIGS. 22A-22F, another alternative embodiment of a tibial insert 1312 is shown. The tibial insert 1312 may be referred to as a constrained condylar knee (CCK) tibial insert 1312 (or “CCK insert”). The CCK insert 1312 may include a fixation side 1320, which may be an inferior side, opposite an articulation side 1322, which may be a superior side. The articulation side 1322 may include a medial articulation portion 1324 having a medial condylar articulation surface 1325 and a lateral articulation portion 1326 having a lateral condylar articulation surface 1327. A central portion 1328 may separate the medial articulation portion 1324 from the lateral articulation portion 1326. A post 1330 may protrude superiorly from the central portion 1328, and extend from a post base 1338 to a top, or post superior end 1340. From the anterior perspective, as shown in FIG. 22E, and the posterior perspective, as shown in FIG. 22D, the post 1330 may have its maximum medial-lateral or horizontal width at the post superior end 1340 of the post 1330, and its minimum medial-lateral or horizontal width at the post base 1338 of the post 1330. The post 1330 may be bilaterally symmetrical from the anterior and posterior perspectives. The CCK insert 1312 may further include a posterior recess 1345, an insert base 1346, and an engagement feature 1348 for engagement with a tibial tray (not shown). An opening 1350 may be present in the superior surface of the post 1330.

The post 1330 may have an articulation surface 1331 extending around the post 1330 on the medial, posterior, lateral, and anterior aspects of the post 1330. The articulation surface 1331 may include a medial articulation surface 1332, a lateral articulation surface 1334, an anterior post surface 1336, and a posterior articulation surface 1342. The medial and lateral articulation surfaces 1332, 1334 may taper slightly inward from the post superior end 1340 to the post base 1338 of the post 1330 relative to an insert midline vertical axis 1302. However, some embodiments of CCK insert 1312 may include less taper, more taper, and/or no taper of the medial and lateral articulation surfaces 1332, 1334. The medial articulation surface 1332 may be continuous with the medial condylar articulation surface 1325, and the lateral articulation surface 1334 may be continuous with the lateral condylar articulation surface 1327. The anterior post surface 1336 may extend between the medial and lateral articulation surfaces 1332, 1334 and may be convexly rounded. The anterior post surface 1336 may taper outward from the post superior end 1340 to the post base 1338 relative to the midline axis 1302, as best seen in FIG. 22F. In other embodiments of the CCK insert 1312, the anterior post surface 1336 may include less taper, more taper, and/or no taper. The post 1330 of the CCK insert 1312 may be wider and bigger in diameter than the post 30 of PS insert 12, for example to provide increased stability in the case of removal of the collateral ligaments. A midline medial-lateral axis 1304 and a mid-line anterior-posterior axis 1306 are also shown in FIGS. 22D through 22F.

Referring to FIG. 22B, the boundary of the post superior end 1340 may define a rounded rim 1344 shaped as a portion of a circle, from a superior perspective, and may have a convex protrusion toward a posterior end of the post 1330. The post superior end 1340 and rim 1344 may be semi-circular as shown, however the rim 1344 may define a circular envelope 1347. The post superior end 1340 may be circular and the rim 1344 may provide increased surface contact and rotational range of motion when coupled and implanted with the PS femoral components disclosed herein in comparison to traditionally shaped posts with a more square or rectangular shaped post. Thus, the rounded post superior end 1340 and rim 1344 may allow for greater surface contact with the femoral components 14, 1014 in contrast to the mere point or edge contact that is achieved by traditional posts that do not include these features.

The CCK insert 1312 may be coupled with the PS femoral components 14, 1014 to form a constrained condylar knee assembly, and this assembly may be implanted with a suitable tibial baseplate as a constrained condylar knee prosthesis. The CCK insert 1312 may also be coupled with any of the CR femoral components disclosed herein and implanted with a suitable tibial baseplate. Thus, all of the tibial inserts disclosed herein are interchangeable with all of the CR and PS femoral components disclosed herein.

Any of the tibial inserts, CR femoral components, and/or PS femoral components disclosed herein may be grouped together in any number or combination as one or more modular knee replacement systems or kits. A particular kit may include a CR femoral component, a PS insert, and a CR insert. Yet another particular kit may include a PS femoral component, a PS insert, a CR insert, and a CCK insert. Suitable tibial baseplate components may also be included with any kit. Moreover, any of the tibial inserts disclosed herein may be formed of vitamin E polyethylene, highly cross linked polyethylene, ultra-high molecular weight polyethylene (UHMWPE), and/or the like.

In an example method of the disclosure, a patient may initially experience compromise of the anterior cruciate ligament. The ACL may be removed, and a CR type prosthesis may be implanted, including a CR femoral component, a CR insert, and a tibial baseplate component. Later, the same patient may experience compromise of the PCL and may need additional stabilization of the knee joint. The PCL may be removed, the CR tibial insert may be removed, and a PS tibial insert of the disclosure may be inserted between the originally implanted CR femoral component and the tibial baseplate component, thus providing additional stability for the missing PCL. Even later, the same patient may experience instability of the collateral ligaments. The PS tibial insert may be removed, and the CCK tibial insert of the disclosure may be inserted between the originally implanted CR femoral component and the tibial baseplate component. Thus, the patient may progress from a CR knee prosthesis, to a PS knee prosthesis, and finally to a CCK knee prosthesis without requiring replacement of the originally implanted femoral and/or tibial baseplate components. The interchangeability of the inserts permits replacement of only the tibial insert component in order to provide increasing levels of support and stability to the knee joint.

In another example method of the disclosure, a patient may initially experience compromise of both the ACL and the PCL. These ligaments may be removed, and a PS type prosthesis may be implanted, including a PS femoral component, a PS insert, and a tibial baseplate component. Later, the same patient may experience instability of the collateral ligaments. The PS insert may be removed, and a CCK insert may be inserted between the originally implanted PS femoral component and the tibial baseplate component. Thus, the patient may progress from a PS knee prosthesis to a CCK knee prosthesis without requiring replacement of the originally implanted PS femoral component and tibial baseplate component.

Referring now to FIGS. 23A-B, FIG. 23A is a perspective front view of the femoral component 1014 of FIG. 14 coupled to one or more augments 1082, 1084 of the present disclosure and FIG. 23B is a medial side view of the femoral component 1014 of FIG. 23A. As briefly mentioned above with reference to FIGS. 14 and 15, the femoral component 1014 may include augment fixation apertures 1080 that may be configured to secure the one or more augments 1082, 1084 to the femoral component 1014, as well as impact driver apertures 1090 configured to receive a femoral component impact driver tool (not shown) to allow a surgeon to press fit the femoral component 1014 to the end of a prepared femur. The augments 1082, 1084 may be secured to the femoral component 1014 with fixation members 1086 and the augments 1082, 1084 may generally act to replace missing and/or compromised femoral bone and allow the femoral component 1014 to be adequately secured to a femoral bone under such conditions.

Referring now to FIGS. 24A-H, a femoral trial component 400 of the disclosure is illustrated in FIGS. 24A-H. In particular, FIG. 24A shows a perspective top view of a femoral trial component of the disclosure, FIG. 24B shows a perspective rear view of the femoral trial component of FIG. 24A, FIG. 24C shows a lateral side view of the femoral trial component of FIG. 24A, FIG. 24D shows a medial side view of the femoral trial component of FIG. 24A, FIG. 24E shows an anterior view of the femoral trial component of FIG. 24A, FIG. 24F shows a posterior view of the femoral trial component of FIG. 24A, FIG. 24G shows a superior view of the femoral trial component of FIG. 24A, and FIG. 24H shows an inferior view of the femoral trial component of FIG. 24A.

The femoral trial component 400 may be referred to as a universal femoral trial component 400 because the femoral trial component 400 may be used as part of a universal femoral trial system for preparing and trialing a femoral bone of a patient (not shown) to receive a plurality of different femoral implant types, as will be discussed in more detail below. The femoral trial component 400 may include a medial condyle 410 having a medial condylar articulation surface 412, a lateral condyle 420 having a lateral condylar articulation surface 422, an attachment aperture 440 located intermediate the medial condyle 410 and the lateral condyle 420, a patellar projection 430 located anterior to the medial condyle 410 and the lateral condyle 420, a patellar articulation surface 432, fixation member drill apertures 470, impact driver apertures 480, medial attachment features 450 proximate the medial condyle 410, and lateral attachment features 460 proximate the lateral condyle 420. The medial attachment features 450 may further include a medial attachment projection 452, a medial attachment aperture 454 formed within the medial attachment projection 452, and a medial attachment recess 456. The lateral attachment features 460 may likewise include a lateral attachment projection 462, a lateral attachment aperture 464 formed within the lateral attachment projection 462, and a co lateral attachment recess 466.

In practice, the femoral trial component 400 may be coupled to a partially prepared distal end of a femur (not shown). For example, a partially prepared distal end of a femur may include five distal cuts that are made to the distal end of the femur using standard techniques and tools (not shown) that are well known in the art. These five cuts may be made to correspond in both shape and angle to the five surfaces on the inner portion of the femoral trial component 400, as best seen in FIGS. 24C and 24D. The femoral trial component 400 may then be press fit onto the partially prepared distal end of the femur and the femoral trial component 400 may also be aligned relative to the distal end of the femur in the medial-lateral directions. The femoral trial component 400 may then be used to further prepare the distal end of the femur and/or perform one or more trial operations with the femoral trial component 400 still in place on the distal end of a femur.

For example, the attachment aperture 440 formed in the femoral trial component 400, along with the medial and lateral attachment features 450, 460, may be configured to receive any of a plurality of removably couplable femoral bone preparation attachments and/or any of a plurality of femoral trial attachments. Example femoral bone preparation attachments may include a posterior stabilizing notch cutting guide assembly 500, an augment cutting guide assembly (not shown), and a drill and broach guide assembly 700, as will be discussed in more detail below. Each of these femoral bone preparation attachments may be configured to removably couple to the universal femoral trial component 400 to allow a femoral bone of a patient to be selectively modified and prepared to receive a selected femoral implant type. Example femoral trial attachments may include a cruciate retaining trial attachment 800 including a cruciate retaining central portion articulation surface 810 and a posterior stabilizing trial attachment 600 including a posterior stabilizing central portion articulation surface 610, as will be discussed in more detail below. The cruciate retaining trial attachment 800 and the posterior stabilizing trial attachment 600 may each be configured to removably couple to the universal femoral trial component 400 to provide a central portion articulation surface 610, 810 above the attachment aperture 440 and allow for trialing of an articulation surface for a selected femoral implant type that includes a medial condylar articulation surface, a lateral condylar articulation surface, and a central portion articulation surface, for the selected femoral implant type. In this manner, the femoral bone preparation attachments and the femoral trial attachments may be used to help finish preparing the femur of the patient to receive any type of femoral component disclosed herein, and/or further perform one or more trial operations with the femoral trial component 400 still in place on the femur, as will be discussed in more detail below.

The femoral trial component 400 shown in FIGS. 24A-H is a right side femoral trial component 400 having a patellar projection 430 with a right angled medial-lateral shape, as best seen in FIGS. 24E and 24F, which mimics the patellar region of a right femur (not shown). Note how the patellar projection 430 angles towards the right in the posterior view of the femoral trial component 400 shown in FIG. 24F and towards the left in the anterior view of the femoral trial component 400 shown in FIG. 24E. A left side femoral trial component (not shown) will have a patellar projection 430 shape that is a mirror image of that shown in FIGS. 24E and 24F, having a left angled medial-lateral shape that mimics the patellar region of a left femur (not shown). In another embodiment of the disclosure illustrated in FIGS. 35A-C, a universal femoral trial component 900 may include a patellar projection 910 with a universal shape that does not angle towards the right or left, but rather, the patellar projection 910 in this embodiment may have a symmetrical medial-lateral shape. In this manner, the universal femoral trial component 900 shown in FIGS. 35A-C has a universal shape that may be used to prepare and trial both right and left side femurs. The patellar projection 910 may have a patellar articular surface 912.

FIGS. 25A-26 illustrate a posterior stabilizing notch cutting guide assembly 500 that may be used with the femoral trial component 400 shown in FIGS. 24A-H to help prepare a femur of a patient to receive a PS femoral component of the present disclosure by guiding bone resection. In particular, FIG. 25A is a perspective rear view of the posterior stabilizing notch cutting guide assembly 500, FIG. 25B is another perspective rear view of the posterior stabilizing notch cutting guide assembly 500, FIG. 25C is a medial side view of the posterior stabilizing notch cutting guide assembly 500, FIG. 25D is a top view of the posterior stabilizing notch cutting guide assembly 500, and FIG. 26 is a partial exploded view of the posterior stabilizing notch cutting guide assembly 500.

The posterior stabilizing notch cutting guide assembly 500 may include a posterior stabilizing notch cutting guide body 510 that includes a medial member 520 having a medial cutting guide surface 522 and medial channels 524 formed therein, a lateral member 530 having a lateral cutting guide surface 532 and lateral channels 534 formed therein, and a patellar member 540 having a patellar cutting guide surface 542.

The posterior stabilizing notch cutting guide assembly 500 may also include a locking mechanism which may include: a first locking member 552, a second locking member 554, a first release lever 562 coupled to the first locking member 552 via a first pin 572, a second release lever 564 coupled to the second locking member 554 via a second pin 574, a first resilient member 592 located between the first release lever 562 and the posterior stabilizing notch cutting guide body 510, with the first resilient member 592 housed in a first resilient member housing 582, a second resilient member (not shown) similarly located between the second release lever 564 and the posterior stabilizing notch cutting guide body 510, with the second resilient member housed in a second resilient member housing 584.

The first resilient member 592 may be configured to apply a biasing force that acts to push the first locking member 552 away from the posterior stabilizing notch cutting guide body 510 in the medial direction and the second resilient member may be configured to apply a biasing force that acts to push the second locking member 554 away from the posterior stabilizing notch cutting guide body 510 in the lateral direction.

Referring to FIGS. 27A and 27B, the posterior stabilizing notch cutting guide assembly 500 may be removably coupled to the universal femoral trial component 400 by squeezing the first release lever 562 and the second release lever 564 together toward each other (see arrows 501 in FIG. 27A) in order to overcome the biasing forces of the first resilient member 592 and the second resilient member; then inserting the posterior stabilizing notch cutting guide assembly 500 into the attachment aperture 440 of the universal femoral trial component 400 (see arrow 502 in FIG. 27A); and finally releasing the first release lever 562 and the second release lever 564 to allow the biasing forces of the first resilient member 592 and the second resilient member to push the first locking member 552 and the second locking member 554 away from the posterior stabilizing notch cutting guide body 510, causing the first locking member 552 to enter within the medial attachment aperture 454 of the femoral trial component 400 and the second locking member 554 to enter within the lateral attachment aperture 464 of the femoral trial component 400 to couple the posterior stabilizing notch cutting guide assembly 500 to the universal femoral trial component 400, as shown in FIG. 27B.

FIGS. 28A-D illustrate a posterior stabilizing trial attachment 600 that may be used with the femoral trial component 400 shown in FIGS. 24A-H to aid performance of one or more trial operations with the femoral trial component 400 in place on the distal end of the femoral bone. In particular, FIG. 28A is a perspective rear view of the posterior stabilizing trial attachment 600, FIG. 28B is another perspective rear view of the posterior stabilizing trial attachment 600, FIG. 28C is a perspective front view of the posterior stabilizing trial attachment 600, and FIG. 28D is a perspective side view of the posterior stabilizing trial attachment 600.

The posterior stabilizing trial attachment 600 may include a central portion articulation surface 610, an internal articulation surface 620 having a medial portion 622 and a lateral portion 624, a cam bar element 630 having a cam bar articulating surface 632, a posterior stabilizing box 670, and a gap 640 formed between the medial and lateral portions 622, 624 within the posterior stabilizing box 670. Each of these components of the posterior stabilizing trial attachment 600, such as the posterior stabilizing box 670 and the cam bar element 630, may be configured to allow for trialing of a complete posterior stabilizing femoral implant.

The posterior stabilizing trial attachment 600 may also include attachment projections 650, 660 on the medial and lateral sides of the posterior stabilizing trial attachment 600. The attachment projections 650, 660 may have shapes that are complementary to the medial and lateral attachment features 450, 460 and/or the medial and lateral attachment recesses 456, 466 that are formed in the femoral trial component 400. In this manner, the attachment projections 650, 660 may be configured to couple to the medial and lateral attachment features 450, 460 and/or the medial and lateral attachment recesses 456, 466 formed in the femoral trial component 400, as shown in FIGS. 29A and 29B. This may be accomplished by holding the posterior stabilizing trial attachment 600 above the femoral trial component 400 and moving the posterior stabilizing trial attachment 600 toward the attachment aperture 440 formed in the universal femoral trial component 400 (see arrow 601 in FIG. 29A) until the posterior stabilizing trial attachment 600 is coupled to the femoral trial component 400, as shown in FIG. 29B. In at least one embodiment, the posterior stabilizing trial attachment 600 may be further configured to magnetically couple to the femoral trial component 400.

In this manner, the posterior stabilizing trial attachment 600 may removably couple to the universal femoral trial component 400 and provide the central portion articulation surface 610 above the attachment aperture 440 of the femoral trial component 400 to allow for trialing of a complete articulation surface for a selected femoral implant type, such as a PS femoral component disclosed herein. A complete articulation surface may include a medial condylar articulation surface, a lateral condylar articulation surface, and the central portion articulation surface 610, for the selected femoral implant type.

FIGS. 30A-31 illustrate a drill and broach guide assembly 700 that may be used with the femoral trial component 400 shown in FIGS. 24A-H to help prepare a femur of a patient to receive a femoral component of the present disclosure that utilizes a keel or other bone fixation member that may require a pre-drilled and/or broached bone aperture. In particular, FIG. 30A is a perspective rear view of the drill and broach guide assembly 700, FIG. 30B is a perspective bottom view of the drill and broach guide assembly 700, FIG. 30C is a top view of the drill and broach guide assembly 700, FIG. 30D is a bottom view of the drill and broach guide assembly 700, and FIG. 31 is a partial exploded view of the drill and broach guide assembly 700.

The drill and broach guide assembly 700 may include a drill and broach guide body 710, attachment projections 750, 760, and a drill and broach guide 720. The drill and broach guide 720 may further include a first drill guide aperture 721, a second drill guide aperture 722, a third drill guide aperture 723, a first broach guide aperture 725 intermediate the first drill guide aperture 721 and the second drill guide aperture 722, and a second broach guide aperture 726 intermediate the second drill guide aperture 722 and the third drill guide aperture 723. The second drill guide aperture 722 may also be located intermediate the first broach guide aperture 725 and the second broach guide aperture 726.

The drill and broach guide assembly 700 may also include a drill and broach guide locking mechanism which may include: a first locking member 742, a second locking member 744, a first release lever 732 coupled to the first locking member 742 via a first pin 752, a second release lever 734 coupled to the second locking member 744 via a second pin 754, and a resilient member 770 located between the first locking member 742 and the second locking member 744 within a locking member housing 780 formed within the drill and broach guide body 710. The resilient member 770 may be configured to apply a biasing force between the first locking member 742 and the second locking member 744 to push the first locking member 742 and the second locking member 744 away from each other.

Referring to FIGS. 32A and 32B, the drill and broach guide assembly 700 may be removably coupled to the universal femoral trial component 400 by squeezing the first release lever 732, and the second release lever 734 together toward each other (see arrows 701 in FIG. 32A) in order to overcome the biasing force of the resilient member 770 between the first locking member 742 and the second locking member 744; then inserting the drill and broach guide assembly 700 into the attachment aperture 440 formed in the universal femoral trial component 400 (see arrow 702 in FIG. 32A); and finally releasing the first release lever 732 and the second release lever 734 to allow the biasing force of the resilient member 770 to push the first locking member 742 and the second locking member 744 away from each other, causing the first locking member 742 to enter within the medial attachment aperture 454 of the femoral trial component 400 and the second locking member 744 to enter within the lateral attachment aperture 464 of the femoral trial component 400 to couple the drill and broach guide assembly 700 to the universal femoral trial component 400, as shown in FIG. 32B. The attachment projections 750, 760 may also have shapes that are complementary to the medial and lateral attachment features 450, 460 and/or the medial and lateral attachment recesses 456, 466 formed in the femoral trial component 400 to aid coupling of the drill and broach guide assembly 700 to the universal femoral trial component 400, as well as magnetic coupling capabilities.

FIGS. 33A-D illustrate a cruciate retaining trial attachment 800 that may be used with the femoral trial component 400 shown in FIGS. 24A-H to aid performance of one or more trial operations with the femoral trial component 400 in place on the distal end of the femoral bone. In particular, FIG. 33A is a perspective front view of the cruciate retaining trial attachment 800, FIG. 33B is a perspective rear view of the cruciate retaining trial attachment 800, FIG. 33C is a perspective bottom view of the cruciate retaining trial attachment 800, and FIG. 33D is a top view of the cruciate retaining trial attachment 800.

The cruciate retaining trial attachment 800 may include a central portion articulation surface 810, an internal articulation surface 820 having a medial portion 822 and a lateral portion 824, and a gap 840 formed between the medial and lateral portions 822, 824. Each of these components of the cruciate retaining trial attachment 800 may be configured to allow for trialing of a complete cruciate retaining femoral implant.

The cruciate retaining trial attachment 800 may also include attachment projections 850, 860 on the medial and lateral sides of the cruciate retaining trial attachment 800. The attachment projections 850, 860 may have shapes that are complementary to the medial and lateral attachment features 450, 460 and/or the medial and lateral attachment recesses 456, 466 that are formed in the femoral trial component 400. In this manner, the attachment projections 850, 860 may be configured to couple to the medial and lateral attachment features 450, 460 and/or the medial and lateral attachment recesses 456, 466 formed in the femoral trial component 400, as shown in FIGS. 34A and 34B. This may be accomplished by holding the cruciate retaining trial attachment 800 above the femoral trial component 400 and moving the cruciate retaining trial attachment 800 toward the attachment aperture 440 formed in the universal femoral trial component 400 (see arrow 801 in FIG. 34A) until the cruciate retaining trial attachment 800 is coupled to the femoral trial component 400, as shown in FIG. 34B. In at least one embodiment, the cruciate retaining trial attachment 800 may be further configured to magnetically couple to the femoral trial component 400.

In this manner, the cruciate retaining trial attachment 800 may removably couple to the universal femoral trial component 400 and provide the central portion articulation surface 810 above the attachment aperture 440 of the femoral trial component 400 to allow for trialing of a complete articulation surface for a selected femoral implant type, such as a CR femoral component disclosed herein. A complete articulation surface may include a medial condylar articulation surface, a lateral condylar articulation surface, and the central portion articulation surface 810, for the selected femoral implant type.

Any of the components disclosed herein may be included in a modular universal femoral trial kit (not shown) to aid in preparing and trialing a femoral bone of a patient to receive a plurality of different femoral implant types. In at least one embodiment, the modular universal femoral trial kit may include a container (not shown) that contains a femoral trial component 400, 900 and at least one femoral bone preparation attachment, such as the posterior stabilizing notch cutting guide assembly 500 and/or the drill and broach guide assembly 700, as one non-limiting example. In other embodiments, the modular universal femoral trial kit may also include at least one femoral trial attachment, such as the cruciate retaining trial attachment 800 and/or the posterior stabilizing trial attachment 600, as another non-limiting example.

FIG. 36 illustrates a flow chart diagram of a method 3000 for preparing and trialing a femoral bone with a universal femoral trial component 400, 900, according to one embodiment of the present disclosure. The method 3000 will be described in connection with the components and instrumentation described herein. However, those of skill in the art will recognize that alternative implants, assemblies, systems, and instrumentation may be used in the performance of the method 3000.

The method 3000 may begin with a step 3010 in which a universal femoral trial component 400, 900 may be placed on an inferior or distal end of a femoral bone. The distal end of the femoral bone may first be partially prepared with five distal cuts that are made to the distal end of the femur using standard techniques and tools (not shown) that are well known in the art. These five cuts may be made to correspond in both shape and angle to the five surfaces on the inner portion of the universal femoral trial component 400, 900 (e.g., see FIGS. 24C and 24D). The universal femoral trial component 400, 900 may then be press fit onto the partially prepared distal end of the femur.

In a step 3020, the universal femoral trial component 400, 900 may be further aligned with respect to the femoral bone along a medial-lateral direction in order to place the universal femoral trial component 400, 900 at a desired medial-lateral location with respect to the femoral bone.

In a step 3030, one of a plurality of femoral bone preparation attachments may be selected in order to guide resection of portions of the femoral bone, as desired. Example, femoral bone preparation attachments may include the posterior stabilizing notch cutting guide assembly 500 and the drill and broach guide assembly 700, as two non-limiting examples.

In a step 3040, the selected femoral bone preparation attachment may be coupled to the universal femoral trial component 400, 900 using techniques described previously herein (e.g., see description related to FIGS. 27A-B and FIGS. 32A-B).

In a step 3050, the femoral bone may be prepared to receive a desired femoral component by using the selected femoral bone preparation attachment as a guide to resect at least a portion of the femoral bone in order to prepare the femoral bone to receive the desired femoral component. Once the femoral bone has been prepared with the selected femoral bone preparation attachment, the method may move to a step 3060.

In the step 3060, the selected femoral bone preparation attachment may be removed from the universal femoral trial component 400, 900.

In a step 3070, one of a plurality of femoral trial attachments may be selected in preparation for performing one or more trial operations with the universal femoral trial component 400, 900 still in place on the femoral bone.

In a step 3080, the selected femoral trial attachment may be coupled to the universal femoral trial component 400, 900 using techniques described previously herein (e.g., see description related to FIGS. 29A-B and FIGS. 34A-B).

In a step 3090, at least one trial operation may be performed with the selected femoral trial attachment coupled to the universal femoral trial component 400, 900, and the method 300 may end. For example, the surgeon may perform trialing of articulation surfaces of the knee joint to ensure that the articulation characteristics of the prosthetic knee joint will be satisfactory.

Various steps of any method disclosed herein may be reordered, omitted, and/or replaced with different steps within the scope of the present disclosure. Those of skill in the art, with the aid of the present disclosure, will recognize that many variations may be made to any other method disclosed herein, depending on the particular surgical procedure to be carried out, as well as the configuration of the system used in the performance of that surgical procedure. Moreover, any methods disclosed herein may include one or more steps or actions for performing the described method. These method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified.

FIG. 37 illustrates a flow chart diagram of a method 4000 for revising a knee joint prosthesis implanted in a knee of a patient to provide increased stability to the knee joint prosthesis, according to one embodiment of the present disclosure. The method 4000 will be described in connection with the components and instrumentation described herein. However, those of skill in the art will recognize that alternative implants, assemblies, systems, and instrumentation may also be used in the performance of the method 4000.

The method 4000 may begin with a step 4010, in which a first knee joint prosthesis that is implanted in a knee of a patient is surgically accessed. The first knee joint prosthesis may comprise a first tibial insert that is located between a tibial base plate component that is implanted on a tibia of the patient and a femoral component that is implanted on a femur of the patient.

The method 4000 may then proceed to a step 4020, in which the first tibial insert may be removed from between the tibial base plate component and the femoral component.

The method 4000 may then proceed to a step 4030, in which a second tibial insert may be inserted between the tibial baseplate component and the femoral component to create a second knee joint prosthesis assembly that is more constrained that the first knee joint prosthesis assembly, and the method 4000 may end.

FIGS. 38A-F and 39 illustrate an example tibial tray 5000 that may be used with any of the tibial inserts and femoral components described herein to create various prosthetic knee assemblies, according to embodiments of the present disclosure. In particular, FIG. 38A shows a perspective front view of the tibial tray 5000, FIG. 38B shows a perspective rear view of the tibial tray 5000, FIG. 38C shows an anterior view of the tibial tray 5000, FIG. 12D shows a posterior view of the tibial tray, FIG. 38E shows a bottom view of the tibial tray 5000, FIG. 38F shows a top view of the tibial tray 5000, and FIG. 39 shows an exploded view of an example tibial tray mounting system 6000 that utilizes the tibial tray 5000.

The tibial tray 5000 may generally include a tibial base plate 5001 that is superiorly mounted on top of a keel 5030. The tibial base plate 5001 may have a superior end 5010 configured to receive any of the tibial inserts described herein, and an inferior end 5020 configured to engage a superior surface of a prepared tibia of a patient (not shown). The superior end 5010 of the tibial base plate 5001 may include a posterior lip 5012 and an anterior lip 5014, each configured to couple to and retain any of the tibial inserts described herein. The superior end 5010 of the tibial base plate 5001 may also include a tibial insert retaining aperture 5050 configured to receive a tibial insert retaining rod 6010, which may be used to further couple to and retain a suitable tibial insert to the tibial base plate 5001, as shown in FIG. 39, provided the tibial insert has a corresponding opening in the post of the tibial insert configured to receive the tibial insert retaining rod 6010 (e.g., see the tibial insert shown in FIGS. 22A-F).

The inferior end 5020 of the tibial base plate 5001 may include one or more spikes 5040 configured to penetrate tibial bone to further couple the tibial base plate 5001 to the superior surface of a prepared tibia. The Keel 5030 may also include a medial fin 5032 and a lateral fin 5034 each configured to penetrate tibial bone and provide additional coupling of the tibial tray 5000 to the tibia. Moreover, in some embodiments the Keel 5030 may also include a tibial stem aperture 5036 configured to receive a tibial stem 6030 and/or a stem adapter member 6020 to further couple the tibial tray 5000 to the tibia of a patient (see FIG. 39). The tibial stem 6030 may be configured to penetrate and reside within an intramedullary canal of the tibia to provide increased fixation of the tibial tray 5000 to the tibia.

It will be understood that the tibial tray 5000 and tibial tray mounting system 6000 shown in FIGS. 38A-F and 39 are merely one example of a tibial tray and tibial tray mounting system that may be used with the tibial inserts and femoral components described in the present disclosure and that other tibial trays and tibial tray mounting systems are also contemplated herein.

Reference throughout this specification to “an embodiment” or “the embodiment” means that a particular feature, structure or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment.

Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, Figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. Thus, the claims following this Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims.

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. Elements recited in means-plus-function format are intended to be construed in accordance with 35 U.S.C. § 112 Para. 6. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles set forth herein.

The phrases “connected to,” “coupled to” and “in communication with” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be functionally coupled to each other even though they are not in direct contact with each other. The term “abutting” refers to items that are in direct physical contact with each other, although the items may not necessarily be attached together. The phrase “fluid communication” refers to two features that are connected such that a fluid within one feature is able to pass into the other feature.

The Figures may show simplified or partial views, and the dimensions of elements in the Figures may be exaggerated or otherwise not in proportion for clarity. In addition, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a terminal includes reference to one or more terminals. In addition, where reference is made to a list of elements (e.g., elements a, b, c), such reference is intended to include any one of the listed elements by itself, any combination of less than all of the listed elements, and/or a combination of all of the listed elements.

The term “substantially” means that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

As used herein, the term “proximal”, “top”, “up” or “upwardly” may refer to a location on the device that is closest to the clinician using the device and farthest from the patient in connection with whom the device is used when the device is used in its normal operation. Conversely, the term “distal”, “bottom”, “down” or “downwardly” may refer to a location on the device that is farthest from the clinician using the device and closest to the patient in connection with whom the device is used when the device is used in its normal operation. Moreover, the terms “upper” and “lower”, and “top” and “bottom”, “front” and “rear” may be used as relative terms herein for ease of description and understanding. It is understood that in embodiments of the disclosure, upper and lower entities may be reversed, as may top and bottom, front and rear.

As used herein, the term “in” or “inwardly” refers to a location with respect to the device that, during normal use, is toward the inside of the device. Conversely, as used herein, the term “out” or “outwardly” refers to a location with respect to the device that, during normal use, is toward the outside of the device.

While specific embodiments and applications of the present disclosure have been illustrated and described, it is to be understood that the scope of this disclosure is not limited to the precise configuration and components disclosed herein. Various modifications, changes, and variations which will be apparent to those skilled in the art may be made in the arrangement, operation, and details of the methods and systems of the present disclosure set forth herein without departing from it spirit and scope. 

What is claimed is:
 1. A knee joint prosthesis system for implantation in a knee of a patient, the knee joint prosthesis system comprising: a femoral component configured to be implanted on a femur of the patient; wherein the femoral component comprises at least one of: a cruciate retaining femoral component; and a posterior stabilizing femoral component; and a tibial insert configured to be implanted between the femoral component and a tibial baseplate component configured to be implanted on a tibia of the patient; wherein the tibial insert comprises at least one of: a cruciate retaining tibial insert; a posterior stabilizing tibial insert; and a constrained condylar knee tibial insert; wherein the posterior stabilizing tibial insert comprises: a medial articulation portion; a lateral articulation portion; a central portion positioned between the medial articulation portion and the lateral articulation portion; and a post protruding superiorly from the central portion along a midline vertical axis, the post comprising a medial side and a lateral side, wherein the medial side and the lateral side each taper inwardly from a superior end of the post toward a base of the post and the medial side and the lateral side each extend at an angle, relative to the midline vertical axis, within the range of 6° to 11°.
 2. The knee joint prosthesis system of claim 1, wherein a superior end of the post is shaped as a portion of a circle, as seen from a superior perspective, and the superior end of the post defines a circular envelope in a cross-section transverse to the midline vertical axis.
 3. The knee joint prosthesis system of claim 2, wherein the superior end of the post is shaped as a portion of a circle, as seen from a superior perspective, and has a crescent shape with a concave recess toward a posterior end of the post.
 4. The knee joint prosthesis system of claim 2, wherein the superior end of the post is shaped as a portion of a circle, as seen from a superior perspective, and has a convex protrusion toward a posterior end of the post.
 5. The knee joint prosthesis system of claim 2, wherein the medial side and the lateral side each extend from the base of the post to the superior end of the post; and the post is widest at the superior end of the post and narrowest at the base of the post.
 6. The knee joint prosthesis system of claim 1, wherein the angle is 6.5°.
 7. A modular knee joint replacement kit, the modular knee joint replacement kit comprising: at least one femoral component configured to be implanted on a femur of a patient; wherein the at least one femoral component comprises at least one of: a cruciate retaining femoral component; and a posterior stabilizing femoral component; at least one tibial insert configured to be implanted between the femoral component and a tibial baseplate component configured to be implanted on a tibia of the patient; wherein the at least one tibial insert comprises at least one of: a cruciate retaining tibial insert; a posterior stabilizing tibial insert; and a constrained condylar knee tibial insert; wherein each of the cruciate retaining tibial insert, the posterior stabilizing tibial insert, and the constrained condylar knee tibial insert are selectively interchangeable such that each of the cruciate retaining tibial insert, the posterior stabilizing tibial insert, and the constrained condylar knee tibial insert may be individually inserted between the tibial baseplate component and the femoral component to form a functioning knee joint replacement; wherein the at least one tibial insert comprises a maximum proximal-distal length, along a proximal-distal direction, that is less than a maximum anterior-posterior length, along an anterior-posterior direction, of the at least one tibial insert, and a posterior stabilizing tibial insert comprising: a medial articulation portion; a lateral articulation portion; a central portion positioned between the medial articulation portion and the lateral articulation portion; and a post protruding superiorly from the central portion, from a base of the post to the superior end of the post, along a midline vertical axis, wherein a superior end of the post is shaped as a portion of a circle, as seen from a superior perspective, and the superior end of the post defines a circular envelope in a cross-section transverse to the midline vertical axis, the post further comprising: a medial side; and a lateral side, wherein the medial side and the lateral side each extend from the base of the post to the superior end of the post, the medial side and the lateral side each taper inwardly from the superior end of the post toward the base of the post, the post is widest at the superior end of the post and narrowest at the base of the post, and the medial side and the lateral side each extend at an angle, within the range of 6° to 11°, relative to the midline vertical axis.
 8. The modular knee joint replacement kit of claim 7, further comprising a package containing the at least one tibial insert, the tibial base plate, and the at least one femoral component.
 9. The modular knee joint replacement kit of claim 7, wherein the superior end of the post shaped as a portion of a circle, as seen from a superior perspective, and has a crescent shape with a concave recess toward a posterior end of the post.
 10. The modular knee joint replacement kit of claim 7, wherein the superior end of the post shaped as a portion of a circle, as seen from a superior perspective, and has a convex protrusion toward a posterior end of the post.
 11. The modular knee joint replacement kit of claim 7, wherein the at least one tibial insert comprises an engagement feature that cooperates with an undercut extending transverse to a proximal-distal direction to secure the tibial insert to the tibial baseplate.
 12. The knee joint prosthesis system of claim 1, wherein the tibial insert comprises an engagement feature that cooperates with an undercut extending transverse to a proximal-distal direction to secure the tibial insert to the tibial baseplate. 